What is the sum of even numbers between 99 and 999?

Answer 1

The sum of the positive integers between 99 and 999 is 299500

Since a = 100, and d = 2 note that the last term will be 998 using nth tem of an Ap

Un= a+(n-1)d

998= 100+ (n-1)2

Then 998- 100= (n- 1)2

= 898= (n-1)2

449= n-1

n= 450

Sum of the terms = n/2(2a+(n-1)d)

450/2(2(100) + 449*2)

Ans= 247050

=

Answer 2

A geometric progression has a common ratio-1/2 and the sum of it’s first 3 term is 18, fin the sum of infinity

Answer 3

(100+998)*450/2=247050

From what I recall this is Gauss figured it out.

Answer 4

247050